package com.shop.dao;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;


/**
 * @author Administrator
 * BaseDao 主要完成 获取数据库连接 和 关闭资源这两个操作
 */
public class BaseDao {
    private static final String DRIVER = "com.mysql.jdbc.Driver";

    private static final String USERNAME = "root";

    private static final String PASSWORD = "123456";

    private static final String URL = "jdbc:mysql://localhost:3306/loginDemo";

    //加载驱动 只执行一次
    static {
        try {
            Class.forName(DRIVER);
        } catch (ClassNotFoundException e) {
            System.out.println("加载驱动失败");
            e.printStackTrace();
        }
    }

    //获取数据库连接
    public static Connection getCon() {
        Connection con = null;
        try {
            con = DriverManager.getConnection(URL, USERNAME, PASSWORD);
        } catch (SQLException e) {
            System.out.println("获取连接失败");
            e.printStackTrace();
        }
        return con;
    }


    //关闭资源
    public static void closeAll(ResultSet res, Statement stmt, Connection con) {
        if (res != null) {
            try {
                res.close();
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }

        if (stmt != null) {
            try {
                stmt.close();
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }

        if (con != null) {
            try {
                con.close();
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

        }

    }

}
